1. Field of the Invention.
The invention concerns novel N-hydrocarbylsulfenyl derivatives of N-alkyl-N'-aryl formamidines, pesticidal compositions thereof and their use in the control of invertebrate pest populations.
2. Description of the Prior Art.
A number of N-alkyl-N'-aryl formamidines have been previously described as pesticides; see for example Belgian Pat. Nos. 760,141; 770,825 and German Pat. Nos. 1,172,081; 2,202,034.
The N-hydrocarbylsulfenyl derivatives of my invention are particularly advantageous commercially as invertebrate pesticides. For example, they are relatively stable both in storage and upon application in the field thus providing a long-lasting residual effectiveness.
In addition to killing invertebrate pests on contact, the compounds of the invention are absorbed by the vascular system of many plants, for example by cotton plants, and act systemically to kill the adult pests feeding upon the plant. Thus their period of pesticidal activity is further extended and non-feeding insects, i.e., insects not harmful to the plant are not unnecessarily killed during the whole period of pesticidal activity.
Compounds of the invention are also ovicidal, and are particularly effective in the control of acarine pest populations by this ovicidal action. Lepidopterous ova are also particularly susceptible to the compounds of the invention.
The compounds of the invention are also advantageous in that they exhibit relatively low mammalian toxicity and are non-phytotoxic at effective concentrations.